1. Field of the Invention
The invention relates to a foldable apparatus comprising first and second parts connected by a hinge, in particular a hand held device such as a mobile phone handset.
2. Description of the Related Art
Mobile phone handsets have several basic configurations. One has a flip down portion which contains only a microphone and is therefore of light construction and requires only a simple hinge mechanism. See, for example, U.S. Pat. No. 6,292,563. However the phone body may also be configured as two parts of substantially equal size, both containing significant parts of the phone. For these phones a more substantial hinge is needed. In particular, the hinge should have a stable open position which can withstand some overstress beyond the stable position.
Known mobile phones typically have mechanical hinges with cylindrical components, and wiring which must be routed around the hinges. U.S. Pat. No. 6,148,480 discloses a hinge construction which is suitable for a handset having substantially equal sized body parts and is also bistable, i.e. gives a snap-open, snap-shut feel. The body parts are molded with barrels having a coaxial bore which receives numerous components including cams and springs which provide the desired action. This complexity adds to the cost of the handset.